There are a great many miles of buried pipeline in the United States, some of which is bare pipe and others of which have various coatings to protect them against corrosion. It is well known that a common source of leakage in both covered and uncovered pipelines is due to galvanic action which causes the formation of corrosion defects which may become larger and larger as time progresses.
Buried pipelines are subject to damage which, when detected, must be corrected. There have been various proposals for repairing defects in underground pipelines such as providing split sleeve type of repair devices which are clamped in place as, for example, in U.S. Pat. Nos. 1,911,126; 2,002,577; 2,046,766 and 2,999,515.
Welded patches have been proposed as for example in U.S. Pat. Nos. 2,236,913; 2,655,946; 3,043,342; 3,053,282; 3,586,057; 3,737,180; 3,746,370.
However, in all of these prior art devices, the repair device must be shaped to fit the particular diameter of pipe involved and with the welded type of repair devices, an inordinate degree of welding is ordinarily necessitated by the nature of the repair device utilized.